Smartphone-Assessed Single-Leg Deadlift Stability is Associated with Sprint Velocity in Youth Soccer Players: A Cross-Sectional Study.

Statistically significant differences were found between higher and lower core stability groups in single-leg deadlift (SLD) test performance.

• Sixteen high-level male adolescent football players were divided into higher and lower core stability groups based on SLD test results.
• The SLD test was assessed using a smartphone application (OCTOcore© app).
• The difference between groups in SLD performance was statistically significant (p = 0.001).

Non-dominant leg SLD performance was significantly associated with 30-m maximal sprint test performance across multiple split intervals.

• Statistically significant differences were observed between non-dominant SLD and 30-m maximal sprint test results (p = 0.001–0.005).
• A large correlation was found between non-dominant SLD and 10-m sprint performance (r = 0.765, p = 0.001).
• Moderate correlations were observed between non-dominant SLD and 15-, 20-, 25-, and 30-m sprint splits (r = 0.508–0.562, p = 0.023–0.044).

No significant relationship was found between SLD core stability performance and change-of-direction speed as measured by the V-cut test.

• No statistically significant differences were found between SLD performance and V-cut test outcomes (p > 0.05).
• No significant correlations were observed between SLD performance and the V-cut test (p > 0.05).
• This suggests core stability as measured plays a greater role in linear acceleration than in multidirectional tasks.

A cross-sectional study design was used with a small sample of sixteen high-level adolescent male football players.

• Sample size was n = 16 high-level male football players.
• Neuromuscular performance was assessed with a 30-m maximal sprint test using 5-m split intervals and a V-cut test.
• Core stability was assessed using a partial range single-leg deadlift (SLD) test evaluated via the OCTOcore© smartphone application.
• Players were divided into higher and lower core stability groups based on SLD test performance.

Core stability is positively associated with sprint performance over 0–30 m but not with change-of-direction speed in adolescent male football players.

• The association between core stability and sprint performance was observed across multiple distances from 10 m to 30 m.
• The strongest relationship was at the 10-m split, indicating a particularly notable role in initial linear acceleration.
• The absence of a relationship with the V-cut test suggests core stability contributions differ between linear and multidirectional movement tasks.